1. Field of the Invention
The present invention generally relates to an electric iron and, more particularly, to a cordless iron and a stand designed to support the iron when the iron is not in use for actual ironing and to conduct heating current to the iron while the iron is placed on the stand.
2. Description of the Prior Art
Cordless irons are not a recent development and are disclosed in numerous patent literature items. For example, U.S. Pat. No. 2,714,650, issued Aug. 2, 1955, discloses an iron system comprising a stand adapted to be placed on a ironing table and including an iron receiving platform and a housing structure at one end of the platform, and an electric iron adapted to be removably mounted on the platform including a heating soleplate and a handle mounted on the soleplate. An electric power supply means is interposed between the iron and the housing structure fast or integral with the platform and comprises a pair of plungers collapsibly supported by the housing structure for movement between retracted and projected positions, and corresponding connector elements carried by the iron and electrically connected with a heating element in the iron.
The plungers are normally biased by corresponding springs to the projected position, but can be moved to the retracted position against the springs when the iron is placed on the stand with the connector elements held in contact with the associated plungers. Movement of the plunger to the retracted position results in the closure of an electric power supply switch encased within the housing to permit the supply of an electric power to the heating element through the plungers and then through the connector elements. In order to ensure a firm electric connection between the plungers and the connector elements, the platform has a toe clip at the other end thereof opposite to the housing structure for engagement with a bow or nose of the iron.
The iron system disclosed in this U.S. patent is a horizontal support model in that the platform is adapted to be placed on the ironing table and is then clamped thereto.
U.S. Pat. No. 2,820,877, issued Jan. 21, 1958, discloses an iron system comprising a stand including a horizontal base and an inclined iron receiving platform and a housing structure at one end of the base, and an electric iron adapted to be removably mounted on the platform including a heating soleplate and a handle mounted on the soleplate. The electric power supply means used therein comprises a double-pole push button, a contact carrier collapsibly supported in the housing structure for movement between retracted and projected positions, and corresponding connector elements carried by the iron at the stern thereof and electrically connected with a heating element in the iron.
The double-pole push button is supported beneath the platform and has a push button adapted to be depressed in response to the placement of the iron on the platform thereby to complete an electric circuit for energizing the heating element.
The iron system disclosed in this U.S. patent is an inclined support model in that the platform is so inclined that, when the iron is placed on the platform, the iron can slide rearwardly by the effect of a gravitational force to establish the electric connection between the contact carrier and the connector elements.
U.S. Pat. No. 3,398,260, issued Aug. 20, 1968, discloses an iron system of the upright support type comprising a stand comprising a plurality of concentric annular sockets delimited by a corresponding number of concentric annular walls and a pair of contact elements exposed to the sockets. The iron has a stern portion formed with concentric annular plugs which are, when the iron is placed on the stand in upright fashion, adapted to be slid into the associated sockets and held in electric contact with the contact elements.
U.S. Pat. No. 3,760,149, issued Sep. 18, 1973, discloses both a horizontal support model and an upright support model of an iron system. In the case of the horizontal support model, connector elements forming parts of the electric power supply means and connected to the heating element in the iron are carried by the soleplate and exposed to the outside through the soleplate, and connector elements forming parts of the electric power supply means and connected to the electric power source are embedded in the platform. A safety switch is employed between the connector elements in the platform and the electric power source in the form of a reed switch adapted to be operated by a magnet carried by the handle of the iron.
In the case of the upright support model, an electric power supply system generally similar to that disclosed in U.S. Pat. No. 2,820,877 is employed.
U.S. Pat. No. 4,650,268, issued Mar. 17, 1987, discloses an iron system of the upright support type wherein, while as the electric power supply means at least one pair of plug pins carried by the iron and a correspondingly one pair of socket receptacles mounted on the stand are employed, a movable baffle is employed to close access openings leading to the socket receptacles that are electrically connected to a power source, thereby to reduce the risk of electrical shock. The baffle can be moved to open the openings in response to the placement of the iron on the stand and, for this purpose, this U.S. patent employs an actuating projection similar to the plug pins and an arm integral or fast with the baffle that is engageable with the actuating projection.
All of these prior art patents are directed to the improvement in electric connection between the iron and the stand. Although the electric connection employed in the prior art iron systems may be satisfactory, they all have the following problems.
When it comes to the cordless iron system, the iron when in use for actual ironing is removed from the stand. As a matter of fact, this means that the supply of electric power to the heating element embedded in the iron is interrupted. Therefore, with increase of the ironing time during which the ironing is performed with the iron removed from the stand, the temperature of the soleplate which has been heated by the heating element decreases progressively and, therefore, the ironing effect to iron out wrinkles in a cloth is reduced. In order to keep the temperature of the soleplate within a tolerance, the iron has to be frequently placed on the stand so that the electric power can be supplied to the heating element. This often brings about reduction in efficiency of the ironing job.
Where the iron has a steaming capability and, therefore, has a reservoir and a pattern of steam nozzles opening from the soleplate, it is known that water in the reservoir is supplied to a vaporizing chamber in which the water is heated to vaporize. Accordingly, when steaming is performed while the iron is removed from the stand with the supply of the electric power to the iron interrupted, the soleplate tends to be cooled by the effect of the latent heat of vaporization. Accordingly, it often occurs that, if one continues ironing without knowing that the temperature has decreased to a value at which the steam is no longer available, water drops escape from the steam nozzles and moisten the clothing being ironed.
A further problem inherent in the prior art cordless iron systems is that, if one leaves the site of ironing with the iron placed on the stand for a substantial length of time, the iron will be excessively heated, enhancing the risk of a fire.
A still further problem inherent in the prior art cordless iron systems is that, since the temperature of the soleplate may be high when the ironing has been finished, one has to wait for a substantial length of time before the soleplate cools down so that the iron and the stand can be put away. During the length of time in which the iron is left on the stand for cooling with the electric system in the stand disconnected from the electric power source, but the temperature is still high, there may be a possibility that a small child may touch the iron and suffer from a burn.